Hobbies And Interests
The pH Concentration
The pH of water is a measure of its acidity or alkalinity. It is represented by a unitless scale ranging from 1.0, which is the most acidic through 7.0, which is neutral, to 14.0, which is the most alkaline. PH is therefore a measure of the hydrogen ion concentration in an ecosystem. It provides a gauge of the relative acid or alkaline nature of a sample. The pH scale is logarithmic, meaning that each pH unit represents a tenfold change in hydrogen iron concentration. Some river ecosystems, such as the Amazon, have an acidic pH, due to the vast quantities of vegetation which is washed into the water from the surrounding jungle. Other river systems have a neutral pH. The life that each ecosystem supports differs because of the water's specific chemistry.
Alkalinity
The alkalinity of aquatic ecosystems is determined by the soil and bedrock the water flows over. Alkalinity refers to the ability of water to resist sudden drops or shifts in the pH of the water. This is achieved by hydroxide, carbonate and bicarbonate compounds in the water, which provide a buffer against a drop in the pH value. Borates and silicates will also boost alkalinity, which is derived from the rocks and soil in the river bed. Water that flows over limestone have a natural high alkalinity, because limestone contains a considerable amount of carbonates. Aquatic systems that flow over granite or sandstone will be low in alkalinity and the water will be termed "soft." Water with a high alkalinity is known as "hard" and these two systems support species that have evolved to thrive only in soft or hard water.
Carbon Dioxide
Carbon dioxide is found in the atmosphere but is also in water. Rocks and sediments store carbon dioxide in aquatic ecosystems and this product, which is also released through the process of chemical weathering or dissolving, is available as either bicarbonate or carbonate ions in the water. Aquatic vegetation use carbon dioxide in the process of photosynthesis, and their growth is important to many aquatic species relying on the plants for food.
Oxygen
Oxygen is a limiting factor in aquatic ecosystems. The amount of dissolved oxygen directly affects the various organisms in an aquatic ecosystem. The dissolved oxygen levels in these systems are influenced by such factors as salinity, altitude and the structure of freshwater rivers or streams. Dissolved oxygen levels in a system are inversely affected by temperature, which influences the amount of oxygen that can be dissolved.